FUNCTIONALIZED CYCLOPENTANE DERIVATIVES FROM THE PHOTOADDUCTS OF METHYL 2,4-DIOXOPENTANOATE-OLEFINS: ALTERNATIVE SYNTHESES OF dl-DEHYDROIRIDODIAL AND dl-CHRYSOMELIDIAL

Functionalized cyclopentane derivatives were prepared by the retro-ozonolys of methyl 2,6-dioxoheptanoates, which are readily accessible from the photocycloaddition of methyl 2,4-dioxopentanoate with olefins. By this method, 3-isopropenyl-2-methoxycarbonyl-1-methylcyclopentene, a versatile intermediate to iridoid terpenoids, and 1-methoxycarbonyl-2,6,6-trimethylfulvene were synthesized from isoprene. Alternative syntheses of dl-dehydroiridodial and dl-chrysomelidial were accomplished.